神经干细胞-脑源性神经营养因子基因工程细胞移植对大鼠缺血性脑损伤的治疗作用

Effect of brain-derived neurotrophic factor genetically modified neural stem cells transplantation on cerebral ischemic injury in rats

目的将脑源性神经营养因子(BDNF)基因转入大鼠海马原代培养的神经干细胞(NSCs)中,获得 NSCs-BDNF 基因工程干细胞并移植治疗大鼠缺血性脑损伤。方法分离培养新生大鼠海马区 NSCs,检测其增殖、分化等特性;构建逆转录病毒载体 pLXSN-BDNF,转染 NSCs,获得NSCs-BDNF 基因工程干细胞,检测其 BDNF 的表达和活性;建立大鼠大脑中动脉局灶性脑缺血模型,通过立体定向技术将 NSCs-BDNF 移植入模型缺血侧海马,进行组织学和行为学检测。结果 NSCs-BDNF 移植后可以观察到动物行为学的改善,术后4周 Longa 评分1.343±0.293,脑切片可以观察到海马齿状回神经元数目的增加,术后4周存活率87.5%±6.6%,较对照有统计学意义(P<0.05)。结论 NSCs-BDNF 移植对实验性大鼠缺血性脑损伤有修复作用。

Objective To investigate the effect of brain-derived neurotrophic factor （BDNF） gene modified neural stem cells （NSCs）transplantation on cerebral ischemic injury in rats. Methods NSCs from newborn rat hippocampus were isolated, cultured in a medium containing fibroblast factor （FGF） in vitro. Their proliferation and differentiation were detected by immunohistochemistry. Virus vectors pLXSN-BDNF were built and BDNF were transfected into NSCs. Biological activity were detected to obtained engineering stem cells of BDNF protein with secretary activity. Middle cerebral artery occlusion （MCAO） models were made and transplanted with NSCs-BDNF by stereotaxic technique. The effect of transplantation on MCAO models was evaluated histologically and behaviorally. Results Statistical analysis showed that the behavioral performance of the animals improved after transplantation （ Longa mark being 1. 343 ± 0. 293 four weeks after stem cell transplantation）. The number of hippocampal dentate gyrus neurons increased to 87. 5% ±6. 6%, four weeks after stem cell transplantation on Nissle stained hippocampal sections, which was significantly different from that of controls. Positively BrdU stained neural stem cells revealed by immunohistochemistry in the cultured cells and in the transplanted brain sections, indicated that the engineering cells transplanted had survived in the host brain and began to proliferate. Conclusion Transplantation of BDNF genetically modified NSCs can effectively promote the recovery from cerebral ischemic injury.